Steam boiler



sept. 15, 1931. A. D. PRATT `1,823,701

STEAM BOILER Filed May l0. 1928 2 Sheets-Sheet l Fig-z m 3Q 4j 35 1 www A* BY K/ sept. 15, 1931. A. D. PRATT 1,823,761

STEAM BoILER y Filed May 10, -1928 2 Sheets-Sheet 2 E i INVENTOR ATTORN Y:

Patented Sept. 15, 1931 UNiTED STATES PATENT OFFICE ARTHUR D. PRATT, OF SHORT' HILLS, NEW JERSEY, ASSIGNOR TO THE IBABCOCK & WILCOX COMPANY, OF BAYONNE, NEWJERSEY, A CORPORATION' OF NEW JERSEY STEAM Application filed May 10,

My invention more particularly relates to a steam boiler comprising a reheater which is advantageously arranged in the boiler and cooperates with the other parts thereof.V

My invention will best be understood by reference to the accompanying drawings, in which I have illustrated a preferred embodi-- ment of my invention, and in whichFig. 1 is a vertical section through a steam boiler embodying my invention, and Fig. 2 is a sectional plan view, the left-hand portion being taken on the line 2-2 of Fig. 1, and the right-hand portion thereof taken on the line aa of Fig. 1.

Like reference characters indicate like parts throughout the drawings. l

Referring now to the drawings, 10 and 11 are upper steam and water drums, and 12 is a lower mud drum connected to the upper steam and water drum 10 by a bank of tubes 13, and to the upper steam and water drum 11 by two banks or groups of tubes 14 which are preferably located at the respective sides of the boiler as best shown in Fig. 2.' One of the side walls of the setting is indicated in Fig. 2 at 141, the wall being provided with an inwardly extending portion as at 142 to form a contracted portion at 143, this portion extending forwardly as at 144 to a bridge wall 18. The groups of tubes 14 are preferably located outside of the plane of the inner surface of the contracted portion 143 of the setting. rlhe tubes 14 are preferably arranged in rows at right angles to the axis of the drum, and the lower portions of the outer three rows of tubes, as shown in Fig. 2, are located in a recess 145 formed between the outermost wall 141 of the setting and the projection 144. Locating at least a portion of some of the tubes in this recess in the described manner, promotes circulation in the tubes.

Tubes 15, arranged in a row parallel t the axis of the drum, are preferably provided having straight portions lying in a' plane immediately in front of and parallel to the tubes 14, but bent at their upper ends and entering the front steam and water drum 10.

The upper steam and water drums and BOILER 1928. Serial No. 276,554.

11 are connected by usual water circulators 16 and steam circulators 17.

A bridgewall 18 is located at the rear of the mud drum 12, and is supported on an I-beam 19.' A baffle 2O extends upwardly from the mud drum 12 at the rear of the front bank of tubes 13, and stops short of the steam and water drum 10. A second battle 21 extends downwardly from the rear steam and water drum 11 between the tubes 14 and the single row of tubes 15, the latter baile stopping short of the lower drum 12.

In the embodiment of my invention illustrated, av superheater illustrated generally at 220, comprises looped tubes 221 connected at one end to anl inlet header 222 in turn connected to the steam and water drum by a pipe 53, the other ends of the tubes 221 being connected to an outlet header 224.

In accordance with my invention, a reheater for heating the steam from the intermediate stages of a steam turbine or other steam engine is employed. Such a reheater is indicated generally at 22, and comprises three headers, 23, 24, and 25, in the embodiment illustrated, located one above the other, the headers 23 and 24 being connected by U-tubes 26 located in a Hue 27 `behind the bridge wall 18 and beside the flue defined between the wall 18 and the baflie 21, the tubes extending back and forth across said Hue. The headers 24 and 25 are connected by U-tubes 28, which preferably extend over and are supported by the bridge wall 18. The ends of the U-tubes 28 are preferably supported by plates 28 which extend upwardly from the bridge wall 18, the ends of the tubes being arranged vin overlapping arrangement with the boiler tubes 14, thereby providing a compact structure which occupies the minimum amount of ioor space. f

A removable door 29 is preferably provided between the headers 24 and 25 through which the U-tubes 28 may be removed, and a removable door 30 is provided between the headers 23 and 24 through which the U-tubes 26 may be removed. The doors and headers form a baille or wall defining the rear portion of the flue 27, this baille or wall being completed by aplate 31 extending upwardly from the header 25 to the roof 32, and a battle member 33 extending downwardly from the header 23, the lower portion of the member 33 preferably being inclined rearwardly as illustrated. Y

A vertical iiue27lcOmmunicatesWith the lower ,portion ofthe .flue 27,; andvinthef1ue 271 is located an economizer indicated generally at 34 and comprising U-tubes 34 extendingacross theflue and connectedftoinl'et. and outlet headers .35. and-36, respectively. ln the flue 271 above the economizer 84 is `preferably located an air heater indicated generally at 37 and comprising tubes 38 .connected at their upper and lower ends, respectively, toftube sheets). and 40 extending.transversely across the flue. Tliegasesfflow upwardly through the tubesBS,l and air preferably flows ina generally `downward direction over the tubes, enteringthespace .surrounding the tubesthroughan .inlet 41,-and.leaving by an air outlet 42,..the gases preferably being directed-overthe Vtubes by angled lbaiies 43,-as shown .in Fig. 1. The-air-heater is preferably; supported by. I-beams 44.

Y 'lheU-tubes 26 and 28 of thereheaterare preferably supported .by rrods-45 extending transverselyacross both banks oftubes, the upper `ends of the rods preferably being supported ,by 'links 46 froinI-beams or other fixed members 47 of the setting.

Ascot pocket 48, which may be supported byv I-beams 49 .and 50, is preferably located beneath theflue 271 and is arrangedto .catch the sootand vdust carried vby thegasesand which are thrown out of the gases where they make the turn from the f1ue27 to. the flue 271. A soot .conveyorl is preferably provided in the .lower portion .of the `soot pocket`48 for the removalof soot and other solidmatter.

The feed inlet is indicated. at.,52 in .the rear steam` and waterdrum 11, and the: steam outletat '53 leading .to a superheater .indicated generally at 220. Aportion of the furnace chamber is indicated at 54above-a furnace not illustrated.

vThe operationof the'boiler embodying my invention will readily be understoodY from the foregoing description andis asfollows:

v.The heated gases from thefurnace chamber 54 'flow upwardly overl the tubes of the front bank 13 and over .the .upper endof the baiiie 20, and then''low downwardly over the single row of tubes 15, andover the superheater tubes 221, and underneathvthe baiile 21, then flowv upwardly .through the. .flue defined by thebaftle 21a-nd the bridge .wall-18 over the rtubes 14. and over the front bent ends of the tubes`28. vThe* Agases then Yfiowdownwardly over the tubes ofy the reheater indicated generally at 22,.around the lower end of the baille .33 into the :flue'271 and thence upwardly over the. tubesof/the economizer and through .the tubesof Vthe air `heater to the stack. Steam preferably enters the header 23 and flows upwardly through the tubes 26 to the header 24, and then through the tubes 28 to the outlet header 25, the steam in the reheater thus flowing in a direction generally counter to .the How of the gases thereover.

It will be seen that with the arrangement described, a comparatively small amount of l boilerfheating-surface is interposed vin `the path' ofl the--furnace-gases between-the furnace and the tubes of the reheater. Furthermore,by arranging some of the tubes of the reheater Ain overlapping arrangement with the'tubes 14 of `the`boiler as viewed longitudinally: of thedrums, the; space ,forthe boiler is bettereutilized The-reheater is :included in aispacebetween.the-levels ofltheupperand lower idrums, 'so .thatno-.additional height .is required in the lstea1n boileigwand .sincel the tubes -overlap with Ithe -boiler l:.tubes, the :minimumfof floorV space ,is required, and the width is less thanf-the combined#width :of: the two. The ,invention is particularly:applicable to a-.-boiler Ahaving vvertically extending tubes, and Aespecially .f a boiler of xthe general vStirling type in which no headers, such -as commonlv fused .with horizontally extending. water tubes, are used.

It. will be Aobvious :that by varyingthes 'relative number of boiler-tubes-iand reheater tubes,- any desired relativeamount:ofasteam generated and reheating-of the :steamzunay befobtained.

A,I claim:l

1. In combinatioma steam boiler. and its setting compri-sing. twoside by side flues, the gases xflowing..upwardly -in I,a first flue.. .and downward-ly in asecond flue,- vertically. extendingfboiler tubes located ,in-saidrrst flue, and relie-aten .tubes having- .portions overlappingv with lsaid boiler f tubes :in said; kfirst flue and VVhaving other portions extending 1 across saidv second; flue.

.2..l'ncombinatiomza steamfboiler and its setting comprisingtwo .sideby sideiflues, boiler tubes located `'in one'of sa.idfluesr,and reheater tubes having one portion of .the tubes located Y.in ,the last-.mentioned flue Vin -overlapping arrangement with Ithe boiler tubes, said reheater tubes .being provided ,with other portions .extending across .said second flue.

In combination, a. steam boiler andits setting comprisingtwo sideA by side vertically extending'flues, boiler tubes located in one of saidflues;and'reheater tubes having one portion of the tubes located in the'lastmentioned "flue 1in overlapping arrangement with theboiler tubes, said're'heatertubes being.y provided lwith .other portions extending across said s second: iue' below said firstmentioned reheatier'ftubes.

4.. In; combination, a steam'v :boiler and kits setting comprising -vtwof side y:by-:side zflues,

boiler tubes located in one of said Hues, and reheater tubes having one portion of the tubes located in the last-mentioned Hue in overlapping arrangement with the boiler tubes, said reheater tubes being provided with other portions extending across said second Hue, the steam Howing through said reheater tubes in a direction generally counter to the How of the gases.

5. In combination, a steam boiler and its setting comprising two side by side Hues, boiler tubes located in one of said Hues, and reheater tubes having one portion of the tubes located in the last-mentioned Hue in overlapping arrangement with the boiler tubes, said reheater tubes being provided with other portions extending across said second Hue, and means for causing the steam to HoW upwardly through said tubes, and the heated gases to How downwardly thereover.

6. A steam boiler and its setting comprising a plurality of upper transverse steam and water drums, a lower drum, a Hue, a circulatory system between said drums comprising tubes connecting said lower drum to one of said upper steam and water drums located in said Hue, a reheater having portions overlapping with said boiler tubes longitudinally of said drums, a second Hue adjacent to the first-mentioned Hue, other portions of said reheater tubes extending across said second Hue, the gases Howing over the overlapping portions of said reheater tubes and then transversely over the remaining portions thereof.

7. In combination, a steam boiler and its setting comprising a first and a second Hue.i boiler tubes located in said Hrst Hue, a reheater comprising tubes extending across and over said second Hue into overlapping arrangement with the boiler tubes in said first Hue, and other reheater tubes located in and extending across said second Hue, the steam Howing through the tubes of said reheater counter to the How of gases over said reheater.

8. In combination, a steam boiler and its setting comprising a Hrst and a second Hue arranged side by side, boiler tubes located in said first Hue, a reheater comprising headers, reheater tubes connecting said headers and extending across and over said second Hue and in overlapping arrangement with the boiler tubes in said first Hue, and other reheater tubes located in and extending across said second Hue, the steam Howing through the tubes of said reheater in a direction generally counter to the How of gases thereover.

9. In combination, a steam boiler and its setting comprising a first and a second Hue arranged side by side, boiler tubes located in said first Hue, a reheater comprising headers, reheater tubes connecting said headers and extending across and over said second Hue and in overlapping arrangement with the boiler tubes in said first Hue, and other reheater tubes located in and extending across said second Hue, the steam Howing through the tubes of said reheater in a direction generally counter to the How of gases thereover, the headers for said reheater forming a part of the Wall of said second Hue remote from said first Hue.

10. In combination, a steam boiler and its setting comprising a Hrst and a second Hue, boiler tubes arranged in two groups and 1ocated on opposite sides of said Hrst Hue, a reheater comprising tubes extending across and over said second Hue and extending between the said two groups of boiler tubes in overlapping arrangement therewith, and other reheater tubes located in and extending across said second Hue, the steam Howing through the tubes of said reheater counter to thek How of gases thereover.

ARTHUR D. PRATT. 

